Extraction Of Metal Extraction

Metal industry is the base of any modern and civilized countries. The demand of metals is growing with the industrial development and advancement in the technology. Metals are extracted from ores, however, the ores usually contain a very small proportion of the targeted metal, e.g. 1~2% for copper and 0.05% for uranium(Hester et al., 1994). As a result, large amounts of impurities are separated during metal extraction. These impurities are waste and need to be safely disposed of. Mining and metal extraction procedures produce waste at different stages. Tailings are generated during preliminary stages of ore beneficiation, and hydrometallurgical wastes are generated during metal extraction.However, the composition of

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Click here to download Manuscript: Non-ferrous metal tailings in China present state anCdli cpke rhsepreec ttoiv veise-w20 l1in3k1e1d0 4R.deofecrences tailings may vary widely from site to site depending on the type of rock mined. In general ores of most of the heavy metals are sulphur-based minerals, therefore there are lots of non-ferrous metal, sulfide mineral, quartz, feldspar, mica and silicate minerals(TISATC, 2011) left in the tailings, with SiO2, CaO, MgO, A12O3, and Fe2O3 as the main chemical component(Sun et al.,2009; Wang et al., 2010).The presence of sulphur causes big problem when this waste comes in contact with air, water and moisture, which transforms sulphur in to sulphate in the series of reaction with due course of time, thereby making the waste acidic with the production of sulphuric acid(Markewitz et al., 2004).On the other hand, for the composition with sulfide mineral, the tailings may be one source of acidic wastewater(Zhao et al., 2011).The non-ferrous metals left in the tailings ar...

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...nsive utilization of iron ore tailings with optimum reaction parameters. Saxena et al.

(2006) investigated addition of copper tailing as an extender for development of paints, and experiments indicated that developed extender is environmentally clean and cost-effective.

While for these technologies, the reaction process was done in laboratories, without much consideration on economic benefits, and most of them may not or rarely be applied in practical production directly. Even though there are suggested advanced technologies, the companies are still reluctant to take part in the recovery in consideration of economic benefits, and they need some financial support, preferential policy and advanced technology transfer from the outside.

(2) Construction materials production

Use tailings for construction materials production, such as Cu, W, and Mo tailings can be made for